Proper purification of waste water requires measurement of electrochemical properties such as pH. In many waste water treatment facilities, and especially those of an industrial nature, the incoming aqueous effluent is an admixture of oily wastes and insoluble sediments. Immersed in such effluents, existing pH monitoring equipment are often rendered inoperable, and at the very least require frequent cleansing maintenance.
Efforts to minimize maintenance and downtime have centered about reducing exposure to the effluent such as by diverting a portion of the process fluid to be tested into a separate housing in which the pH electrodes are inserted. However, this procedure has heretofore demanded costly permanent sampling installations at each location where pH is to be monitored. Additionally, the housing and electrodes still have needed frequent maintenance and been subject to failure as a result of oil and sediment build-up in the vicinity of the electrodes. Although several approaches have been taken to clean the electrodes during operation, including oscillating motor-driven wipers, ultrasonic vibrations, and timed jets of cleansing solution aimed at the electrodes, all have required complex and expensive independent structure to effectuate.